The present invention relates to a photoelectric device and, more specifically, to a photoelectric device having a package containing a laser chip which emits laser light, and an optical fiber cable which guides the laser light emitted from the laser chip outside the package.
A semiconductor laser device is used as a light source for the optical communication system. An exemplary laser module, namely, a semiconductor laser device, for the optical communication system is published in "Hitachi Hyoron", Hitachi Hyoron Sha, No. 10, pp. 39-44, Oct., 1983. This semiconductor laser device is of a so-called direct disposition system, in which the free end of the optical fiber is disposed opposite to the resonant end face of the semiconductor laser element, and is formed in a flat module having a box-shaped package. This semiconductor laser device has a metallic stem with the central portion of the main plane thereof sealed by a cap formed of a metallic plate and is provided internally with a semiconductor laser element (laser diode chip) and a light receiving element which detects the optical output of laser light emitted from the resonant end face of the laser diode chip. Further, this semiconductor laser device employs a laser diode chip which emits a laser light of a 1.3 .mu.m band, and a single-mode optical fiber for long-distance large-capacity communication. In this semiconductor laser device, the free end of the optical fiber facing the light emitting surface of the laser diode chip are supported on a positioning shaft, which is bent to adjust the position of the free ends of the optical fiber for optical axis alignment.
The applicant of this patent application has proposed a technique to improve the efficiency of the optical connection of the laser diode chip and the optical fiber of a semiconductor laser device in Japanese Patent Application No. 58-151560. According to this technique, the free end of the optical fiber is held by a flexible holder, and an external force is applied to the head of the flexible holder after fixing the optical fiber and the laser diode chip to adjust the position of the free ends of the optical fiber so that the respective optical axis of the optical fiber and the laser diode chip are aligned with each other.
A light emitting module for optical communication is published in "NEC Giho", Vol. 38, No. 2, pp. 84-89, 1985. This light emitting module comprises, in a package, a laser element which emits a laser light, a Ge-PD (light receiving element) for monitoring the back radiation of the laser element, a thermistor for monitoring the temperature of the laser element, and a Peltier element functioning as a temperature regulating cooler; an optical fiber cable for transmitting the laser light outside the package is connected to the package. The light emitting module is a dual in line package. The laser element and the thermistor are mounted on a block fixed on the Peltier element, while the optical fiber is secured to the block. The light receiving element is fixed to the block.
In either foregoing semiconductor laser device, the optical fiber is disposed with the free end thereof opposite the laser diode chip and are held fixedly at a position near the wall of the package and at a position near the laser diode so as to extend linearly between the two positions.